Beam

ABSTRACT

A flanged beam with a web structure formed of a wire or strip-like member (2) bent to zigzag, meander or wave configuration, the bending spots (3) thereof being attached to the flanges (1). The specific feature of a beam performed according to the invention is that at least one flange (1) incorporates a flange section extending alongside this flange. The flange section, which is made of another material than the rest of the flange, is embedded in the flange and is cast to form a unit with it and with the bending spots (3) of the wire or strip-like member (2) which spots are connected with the flange.

The present invention relates to a flanged beam with a web structureformed of wire or strip-like members bent into zigzag, meander or waveshape and having their bending points secured to the flanges.

BACKGROUND

A beam of this type and a method of manufacturing it is described ine.g. Swedish Lay-Open Print No. 7610600-4. The usage of this as well asother beams is however limited by the bearing capacity and bendingproperties. These qualities are primarily dependent on the properties ofthe wooden flanges and on the degree of deformation of the wood at thepoints where the web of bent metal wire or strip is secured to theflanges. The wood comprised in the flanges must therefore be classifiedand jointed with great accuracy while complying with the stipulatedrules, which is a both complicated and costly procedure. As disclosed inthe published "SE-B-" No. 415 991, certain attempts have been made toovercome these drawbacks by attaching wire, extending in thelongitudinal direction of the flanges, by welding it to the bendingspots of the web. Unfortunately however, this has resulted inproductional complications setting aside the economical profit gained bythe increased rigidity and bearing capacity of the beam, despite theadvantage that a lower quality of wood can be used for the flanged. Infact, welding of the wire extending along the flanges to the bendingpoints of the web must necessarily take place prior to theanti-corrosive treatment of the wire included in the web structure,which treatment cannot be neglected. Beyond being expensive per se as itmust be performed individually for each separate unit of the almostlattice-resembling webs created by the wire members welded to thebending points, this anti-rust treatment also eliminates thepossibilities of rationally manufacturing finished webs by thecontinuous bending of an already surface-treated wire taken directlyfrom a supply coil.

SUMMARY OF THE INVENTION

The object of the invention is therefore to suggest a novel and improvedtype of beam in accordance to what is set forth by way of introduction,which solves the above-described problems associated with the previouslyknown beams and which, despite its more solid and deformation-resistantstructure, enables a simplified and less expensive manufacture of beamsthan has been possible so far.

In order to fulfill its purpose at least in all essential parts, a beamconstructed according to the invention is mainly characterized in thatat least one flange has a section extending longitudinally with theflange and consisting of another material than the rest of it, and whichis embedded in the flange while being cast to form an integral unittherewith and with the bending spots of the wire or strip-like memberfixed thereto.

By means of embedding flange sections into the beam flanges, thesesections thereby forming a unit not only with the flange but with theweb as well, this web structure can be manufactured in a most simplemanner from already surfacetreated wire or strip material taken from astorage coil, the invention simultaneously safeguarding a particularlystable deformation-reluctant connection between the bending points ofthe web and the flanges.

A further, especially important advantage gained by the invention isthat the main part of the rigidity and the supporting capacity of thecompleted beam can, if desired, be transferred to the embedded flangesections, whereas the design of remaining flanges and the materialselected therefor can be adapted primarily for nailing and screwing,temperature insulation or any other desirable purpose. As a consequencefor example, the quality of the wooden flanges need not be too high, andneither the classification nor the splicing or jointing of the wood needbe done with the aid of any sophisticated or costly methods. With theappropriate dimensions and a suitable material selected therefor, theembedded flange sections will constitute the elements taking up most ofthe load in the beam, relieving in this way the wooden material in theflanges from the greater part of its load-bearing function. In ordinarybuilding beams there are required for this purpose only comparativelysmall crosssectional areas for the flange sections. Sectional areas assmall as one or a few square centimeters will in fact affordconsiderable reinforcing effects to the beam.

In a preferred embodiment of a beam performed according to theinvention, at least the main part of the embedded flange section isdisposed in a long channel or groove-like space in the flange,accommodating at least partially the wire or strip-like portions joinedto this flange. Without applying the elaborate procedure of woodclassification and preparation of wood/metal wire connections associatedwith the previously known beams, similar beams can be manufacturedaccording to the invention simply by providing a channel or groove alongthe whole length of the wooden flanges, said groove then serving as amould when applying the other material intended to form the embeddedflange section in accordance with the invention.

In order to ascertain a really efficient cast integration between theembedded flange section and the portions of the web-forming wire orstrip-like members disposed inside a flange, the long groove-like spacehas a bottom which is in communication with additional spaces intendedfor these web portions.

The section embedded in a flange and consisting of another material thanthe rest of the flange can either be disposed on the side of the flangefacing away from the web, or on the side facing towards it. In thelatter case the other flange sections will be more easily accessible fornailing and screwing for example, whereas in the former case theembedded flange section has a more active load-absorbing function due toits placement further away from the so-called neutral surface of thebeam.

As embedded flange section of the inventive kind can be made from avariety of compounds of which several plastics with the appropriateamount of fillers seem to be the most useful materials at least forbeams in building constructions, and the flanges themselves can be madeof wood or the like material fitted for nailing and screwing. Examplesof suitable plastics are polyester, acrylate, polyurethane, epoxy resinor similar compounds, which may preferably be reinforced with steel orglass fibre, mica or any other material contributing to the strength ofthe embedded flange section.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail below while referring toan exemplary embodiment of the inventive beam, shown on the drawing.

FIG. 1 in the drawing is a partially cut away perspective view of a beamaccording to the invention, primarily intended for use in the buildingindustry, whereas

FIGS. 2-4 are three cross-sectional views of such a beam.

DETAILED DESCRIPTION

As can be seen from the drawing, a beam according to the invention hastwo chords or flanges 1 interconnected by a web structure, the beamtherefore being regarded as a type of I-beam. The web structure howeveris formed of a wire or strip-like member 2 bent for example into zigzag,meander or wave shape and having its bending points 3 connected to theflanges 1, the similarity to a conventional I-beam therefore beingincomplete.

According to the invention, the two flanges 1 include a long flangesection 4 made of another material than the rest of the flange andextending along the length of each respective flange while beingembedded therein and cast to form an integral part of the flange and ofthe bending points 3 of the wire or strip-like member 2, which pointsare also connected to the flange.

The wire or strip-like member 2 in the embodiment of the inventive beamconsists of properly dimensioned steel wire which is bent to theillustrated configuration after having been treated with the necessaryanti-corrosive agent. In order to permit screwing and nailing, the mainpart of the flanges are preferably made of wood, for example studsmeasuring 2×2". Alternatively, different kinds of wood fibre or chipmaterial can be used for this purpose. In the present embodiment, theflange sections 4 embedded in the flanges 1 may preferably consist of aplastics material mixed with a certain amount of filler and reinforcedin order to make the finished, embedded flange section sufficientlystrong for taking up at least the main part of the load to which thebeam may be subjected during use. Examples of plastics materials usefulfor the embedded flange section according to the invention arepolyester, acrylate, polyurethane, epoxy resin or similar compounds,whereas steel or glass fibre, mica or the like are suitablereinforcement agents.

As shown in the drawing, the embedded flange sections 4 are at leastprincipally disposed in long spaces formed as grooves 5 in the flanges1, said grooves or spaces 5 partially accommodating those portions ofthe web-forming, wire or strip-like member 2 which are united with theflanges. For casting together these web portions with the flangesections embedded in the flanges, the long channel-like spaces 5 have abottom to which are connected further recesses 6 for the portions of theweb member 2 disposed inside the remaining flange portion.

In the embodiment shown here, exemplifying a beam performed according tothe invention as illustrated in FIGS. 1 and 2, the embedded flangesections 4 are located at the sides of the flanges 1 facing away fromthe web 2. As can be seen from the flange cross sections illustrated inFIGS. 3 and 4 however, they can alternatively be placed on the sides ofthe flange 1 directed towards the web 2, or even such that one embeddedflange section 4 is situated on the side of one flange 1 facing awayfrom the web 2, whereas the embedded flange section 4 of the oppositeflange 1 is situated on the side thereof turned towards the web 2.

The invention is not restricted to the example described and illustratedherein but can be modified in many ways within the scope of thefollowing claims.

What is claimed is:
 1. A longitudinally extending beam having alongitudinal direction and having flanges made from a first material anda web structure formed of a wire or strip-like member bent into zig zag,meander or wave shape, said member having bending points secured to theflanges, characterized in that at least one of the flanges comprises alongitudinally extending flange section made of a material differentfrom the first material of the flange and extending in the longitudinaldirection of the flange and being embedded in said rest of the flangeand cast to form a unit with said rest of the flange and with thebending points of the wire or strip-like member being joined to theflange section, said flange section material extending a distance in thelongitudinal direction coextensive with at least one of said flanges,where at least two bending points are imbedded in said material which iscoextensive with said flange.
 2. A beam as claimed in claim 1,characterized in that the embedded flange section (4) is at least mainlydisposed in a long channel-like space (5) in the flange (1), said spaceat least partially accommodating portions of the wire or strip-likemember (2) connected to said flange.
 3. A beam as claimed in claim 2,characterized in that the long channel-like space (5) accommodating theembedded flange section (4) has a bottom which is in communication withadditional spaces (6) for portions of the wire or strip-like member (2)disposed inside said flange (1).
 4. A beam as claimed in claim 1characterized in that the embedded flange section (4) is situated on theside of the flange (1) facing away from the web (2).
 5. A beam asclaimed in claim 1 characterized in that the embedded flange section (4)is situated on the side of the flange (1) facing towards the web (2). 6.A beam as claimed in claim 1 claims, characterized in that the embeddedflange section (4) consists of a plastics material supplied with acertain amount of filler such as polyester, acrylate, polyurethane,epoxy resin or the like, reinforced with steel or glass fibre, mica orany other product contributing to the strength of the flange section. 7.A beam as claimed in claim 1 claims, characterized in that the remainingportion of the flange (1) at least essentially consists of wood, woodchip or wood fibre, or any other material suited for nailing orscrewing.
 8. A beam having a longitudinal dimension comprising: twospace-apart, parallel flanges at least one of which includes alongitudinally extending member of wood material having a continuouslongitudinal channel in a face thereof and coextensive with the flange,the channel containing a continuous flange section of plastics materialcast into the channel and coextensive therewith, the flange sectioncontaining reinforcing elements, the beam further comprising a metal webof generally zig-zag configuration located between the flanges, the webhaving a plurality of longitudinally spaced apart bent portions incontact with and joined to the continuous flange section, said plasticsmaterial extending a distance in the longitudinal direction.
 9. A beamhaving a longitudinal dimension comprising: two spaced-apart parallelflanges each constructed of wood material and each flange having acontinuous longitudinal channel in a face thereof and coextensive withthe flange; a metal web of generally zig-zag configuration locatedbetween said flanges, the web having a plurality of longitudinallyspaced-apart bent portions disposed in one of the channels and flangesections of plastics material cast into said channels and around saidbent portions of said web, said cast flange sections being coextensivewith said channels and being joined to said bent portions of said web,and said cast flange sections being the sole longitudinally extendingreinforcement for said flanges.